Bush for reciprocating members



, Oct. 20, 1931. A. G. 'M. MICHELL 1,828,289

BRUSH FO R BECIPROCATING MEMBERS Filed Feb. 8, 1928 if /g4 1 E v 3 Patented a. 20, 1931 UNITED STATES PATENT, OFFICE ANTHONY GEORGE WON HIOHELL, OF MELBOURNE, VICTORIA, AUSTRALIA, AS-

SIGN'OB, BY HESNE ASSIGNMENTS, TO MIGHELL-GBANIIESS HGINES OOBPORL- TIONJ)! NEW YORK, N. Y A. GQRPORA'I'ION' OF NEW YORK nUsE roamiorraooarme immune Application fled February 8, 1928, Serial 1T0. 852,890, and in Great Britain February 22, 1887.

As shown in Fig. 1, the single-acting piston This invention relates to improvements in the hollow cylindrical members, known as bushes, commonly employed in numerous classes of machines and especially in reciprocating engines, as guide members for reciproeating cylindrical rods fitting within them. It is usual to construct such bushes in one piece, but they are sometimes, for reasons of easyassembly or otherwise, formed in two or more so ents of a more or less complete 0 linder. lgiishes constructed accordin to tile present invention are of the latter c ass.

The object of the invention is to provide the conditions necessary for efiective lubrication of such bush members, while at the same time providing means for preventing excessive 'fiowbf oil past the bush, and thus to enable bush members of comparatively simple type to be used in cases where it has been customary to use stufling-boxes or special scraping devices, as for example upon the piston-rods of high-speed steamengines and air compressors to prevent transfer of oil ,from their crank-chambers to their cylinders.

The invention is particularly applicable to en es of the crankless type, but is not revariously pivoted and adapted to set up invention consists of a bush formed of two or more segments collectively acting as a for a reciprocating rod, said segments separate tilting movements about axes trans verse to the axis of said rod, so that the tilting varies over the several se ents to permit through flow of lubricant n reverse directions longitudinally through the bush, with which may be combined elastic means arranged towards one or other end of each of the se ents urging the same into contact with t e reciprocating rod.

In the accompanying drawings, Fig. 1 is a lon 'tudinal view of'apiston and rod, the bus being shownQin a longitudinal section. Fig. 2 is in part an end view of the bush, and in part a cross-section on line II, II of Flg. 1. Figs. 3 and 4 are partial lon itudinal views corresponding to Fig. 1 and illustrating the action of the parts of the bush.

either type of engine owever, vif oi the single-acting class, the rod 3 may be or the I full diameter of the piston, thus forming a trunk rod, or extension of the piston itself.

The bush illustrated which is constructed in accordance with this invention consists of two or more segments 4, 4a (six being shown a in Fig. 2) which together form a nearly complete cylindrical ring of which the inner surj face fits the rod 3. Each segment is pivotally supported with respect to the stationary part of the machine by a spherical projection 5 or 5a thereon fitting in one or other of two recesses 6, 6a. These recesses are preferably formed in a sleeve-member 7 fixed in an exa tension 8 of the wall of the cylinder 2. Surrounding the outer ends of the segments 4, 4a (that is to say, the ends remote from the piston 1), is a garter spring 9 which tends to draw all the segments 4, 40 together and into contact with the rod 3. The tension of the spring 9 is however adjusted so as to exert lighter radially inward forces on the se ments than the principal lateral or radialfy outward pressures which the latter receive from the rod 3; the direction of the radial forces may change periodically in ,various ways according .to the type of engine or other machine.

Each segment 4 or 4a has its pivotal projection 5 or 511, located either in the inner recess 6 or outer recess according as pressure is or is not exerted on that segment by the rod 3 during its inward stroke. Thus, as shown in Fig. 3, the lower se ent 4 is as- 5 sumed to be subjected to a 10a P (due to the weight of the piston 2 and rod 3 or to the thrust of a connecting-rod or the like), while the rod 3 is moving inwardl to the right as shown by the arrow A; the ower segment 4 is therefore mounted with its pivotal projection 5 in the inner recess 6.

Under these conditions, the segment 4 being subjected to the load P which concentrates on its trailing end because of the yielding support provided at its inner end, tilts as shown in an exag erated manner in Fig. 3 so as to form a we ge-shaped film of oil between its interior sur ace and the rod 3,, and a flow of oil takes place through this film in the inward direction of the arrow A.

The upper segment 4a, being subjected only to the yielding pressure of the spring 9 at its leading end, remains in close contact with the l)d 3, and permits little or no inward flow of o In the return stroke of the rod 3, as shown by Fig. 4, the segment being assumed to be now subjected to the force P from the rod 3 and this force P, which again concentrates at the trailing end, being greater than the inward pressure of the spring 9, the segment 4a now tends to tilt as shown in the figure so as to form a wed e-shaped film of oil between its interior surface and the rod 3, and to permit a flow of oil from its inner to its outer end in the direction of the arrow A. At the same time, the lower segment 4, being now subjected only to the yielding upward ressure of the spring 9 at its trailin end, li ewise tilts as shown and allows a ow of oil from its inner to its outer end in the direction of the arrow A. Thus accumulation of oil at the inner end of the bush, and a transference of oil into the cylinder 2 are revented, while the segments of the bush sub ected to pressure by the rod 3, are effectively lubricated. As an auxiliary means of preventing accumula tion of oil while the engine is stationary, or working under abnormal conditions, a recess or chamber 10, may be formed in the cylinder wall at the inner end of the bush, this chamber and the recesses 6, 6a, being drained by oil-ways 11, 12 and 12a res ectively.

It is to be understood t at the form of the projections 5, 5a, and recesses 6, 6a hereinbefore described and shown in the figures, are subject to modification according to circumstance, their essential features being that they permit of the pivoting of the segments 4, 4a, at their inner and outer ends respectively.

It is likewise to be understood that the spring 9 is described and illustrated as a garter-spring only by way of example, and that i any other form of spring or springs suitable for maintaining inward pressure of these ments of the bush towards one of their en s may be substituted.

I claim 1. A bush for a reciprocating. rod, comprisin a plurality of segments pivoted adj acent t e ends thereof and having bearing surfaces adapted to engage the rod.

2. A bush for a reciprocating rod, comprising a plurality of segments having bearing surfaces adapted to engage the rod, said segments being pivoted on axes offset from the longitudinal centers of the segments and transverse to the axis of reciprocation of said rod.

3. A bush for a reciprocating rod, comprising a plurality of pivoted segments havin bearing surfaces adapted to engage the rm i, and resilient means for pressing the segments against said rod.

4. A bush for a reciprocating rod, comprising a plurality of pivoted segments having bearing surfaces adapted to engage the rod, certain of said segments being p1voted adjacent one end of the bush, and others geing pivoted adjacent the other end of the ush.

5. A bush for a reciprocating rod, comprising a plurality of pivoted segments having bearing surfaces adapted to engage the rod, and resilient means for pressing the segments against said rod, said resilient means engaging certain of said segments adjacent the pivoted portions thereof and engaging other segments adjacent portions remote from the pivoted portions thereof.

6. A bush for a reciprocating rod, comprising a plurality of pivoted segments having bearing surfaces ada ted to engage the rod and resilient means or exerting an inward pressure in said se ents, said resilient means acting on certain of said segments remote from the pivots thereof.

7. A bush for a reci rocating rod, comprising a plurality of pivoted segments havmg bearing surfaces ada ted to engage the rod and resilient means or exerting an inward pressure in said segments, said resilient means acting on certain of said so cute remote from the pivots thereof, an on other 1 segments adjacent the pivots thereof.

8. A bush forming a lubricated guide for a reciprocating rod, comprising a plurality of segments pivoted on axes transverse to the axis of said rod.

9. A bush forming a lubricated guide for tiltable on pivots adjacent one end of prising a lurality of segments, a pivotal mounting or said segments, said se ents being pivoted on axes transverse to e axis of the ush to hold the segments against longitudinal movement with the rod as the rod 1s reciprocated.

12. A hush for a reciprocating rod, comprising a ho disposed within said housing, said segm using, a-plurality of segment:

bein mounted for pivotal movement in said '5 housing on taxes transverse to the axis of the housing.

In witness whereof I have signed this specification. A

NTHORY GEORGE "ALDON MlCHEl-L. 

